Fluid sealing devices

ABSTRACT

A sealing device suitable for use in a control valve which has a slidable valve member with a greater diameter portion engageable within the sealing device to close a valve passage, wherein the sealing device includes a resilient sealing ring and a supporting ring which interlock. The sealing ring has a radially-extending portion providing an inner sealing face which is engageable by the valve member, and an axially-extending portion which is engageable within the body of the control valve. The supporting ring is disposed radially within the axially-extending portion and on one side of the radially-extending portion.

Underwood 1451 Jan. 9, 1973 s41 FLUID SEALING DEVICES 2,823,058 2/1958Eckeretal. ..277/188X 3,081,061 3/1963 Conrad .....251/358X [75]Inventor: Cyril James Underwood, Coberley, 2,970,371 2/1961 FlickEngland 2,661,182 12/1953 Kipp ..251/D1G.1 [73] Asslgnee: gf ip g?:ewkesbury Primary ExaminerArnold Rosenthal oucesters an Att0mey-Young &Thompson [22] Filed: Dec. 3, 1970 57 ABSTRACT [21] Appl. No.: 94,792 1 Asealing device suitable for use in a control valve which has a slidablevalve member with a greater Foreign Application Primity Data diameterportion engageable within the sealing device Dec. 18, 1969 Great Britain..61,852/69 close a l"? F' the Sealing i cludes a res111ent sealing ringand a supporting ring which interlock. The sealing ring has aradially-ex- [52] US. Cl. ..277/l88, 277/194, 22551/358, t6ding portionproviding an inner Sealingface which 51 I 1/324 is engageable by thevalve member, and an axially-exnt. Cl ..F16k 3/24 tending portion whichis ehgageahle within the body [58] Field of Search ..25l/36l, 363, 358,324; of the centre] valve The Supporting i i di d 194,193 radiallywithin the axially-extending portion and on one side of theradially-extending portion. [56] References Cited 3 Claims, 3 DrawingFigures UNITED STATES PATENTS 3,134,601 5/1964 Hager ..277/l93 X 77 7337 2 5 4 it: 15 76 1 1' I 1 1 v 28 U 29 FLUID SEALING DEVICES Thisinvention relates to sealing devices suitable for use in fluid flowcontrol valves, and also to fluid flow control valves incorporating suchsealing devices.

According to the present invention a sealing device comprises a sealingring of resilient material having a radially-extending portion and anaxially-extending portion, the radially-extending portion providing aninner sealing face, and the radially and axially extending portionsproviding an outer sealing face, and a supporting ring of a materialharder than that of the sealing ring, the supporting ring being disposedradially within the axially extending portion and on one side of theradially-extending portion, and having an interface with said portionswhich is shaped to provide interlocking engagement with the sealingring.

Sealing devices in accordance with the present invention are suitablefor use in fluid flow control valves of the kind in which a spool typeof valve member has portions of greater and lesser diameter whichcooperate with a sealing device respectively to close and to open afluid flow connection across the sealing device.

The invention is illustrated in the accompanying drawings, of which:

FIG. 1 is a longitudinal sectional view of a fluid flow control valve,in which the parts above and below the horizontal midline show themovable valve member in different positions,

FIG. 2 is a sectional view on an enlarged scale of the sealing device inFIG. 1, and

FIG. 3 is a sectional view of an alternative form of sealing device.

The valve of FIG. 1 has a housing 11 formed with a bore 12, and twoports 13 and 14 which open into the bore at positions spaced apart alongthe axis of the bore. Covers 15 and 16 at opposite ends of the housing 11 have openings with recesses containing sealing rings 17 and 18 throughwhich a movable valve member 19 is axially slidable. The valve member 19is for the most part of a uniform greater diameter which fits theopenings in the covers 15 and 16, but which is radially spaced from thebore 12. A portion 21 of a lesser diameter leads into a frusto-conicalportion 22 which intersects the greater diameter portion at a circularedge 23. This edge may be somewhat rounded.

Two lantern rings 24,25 are mounted in the bore 12 adjacent therespective ports 13 and 14, these rings having radial orifices 26therein. The lantern rings form spacers for locating a sealing device 27in the bore 12 at a position between the ports 13 and 14. In the upperpart of FIG. 1, the valve member 19 is retained by an end stop 28against the cover 15, in a position in which the greater diameterportion of the valve member 19 engages the sealing device 27 whereby theports 13 and 14 are isolated one from the other. In the lower part ofFIG. 1, the valve member 19 is retained by an end stop 29 against thecover 16, in a position in which the lesser diameter portion 21 isradially spaced from the sealing device 27 to afford a connectionbetween the ports 13 and 14.

The sealing device of FIG. 2 includes a resilient sealing ring 31 havinga radially-extending portion 32 which provides an inner sealing face 33engageable by the greater diameter portion of the valve member 19.

The sealing ring also includes an axially-extending portion 35 which,together with the radially-extending portion, provide an outer sealingface 34 for engagement with the bore 12. The axially-extending portionis inwardly defined by a cylindrical face 36 having an annular recess 37therein. A supporting ring 38 of a material harder than that of thesealing ring 34 is received radially within the axially-extendingportion and on one side of the radially-extending portion of the sealingring 31. The supporting ring 38 fits the cylindrical face 36 and it isformed with a flange 39 which fits the annular recess 37, and it alsoengages one side of the radiallyextending portion in a transverse matingplane. The supporting ring thus has an interface with the portions 32and 35 which provides interlocking engagement with the sealing ring.

The sealing device is assembled by springing the sealing ring 31 on tothe supporting ring 38. The assembled sealing device has a substantiallysquare cross section. The axial length of the supporting ring 38 exceedsthe axial length of the radially-extending portion 32 of the sealingring 31. The axial length of the radially-extending portion is smallcompared with the radial width.

The bore of the supporting ring 38 provides a clearance fit for thevalve member 19, but the radiallyextending portion 32 projects slightlyinwardly from this bore in its free state whereby it is compressed bythe greater diameter portion of the valve member 19 when installed inthe valve.

The valve is operable with the higher fluid pressure in either the port13 or the port 14. If the higher pressure is in the port 14, the fluidpressure will case the sealing device 27 to engage the lantern ring 24,and the latter to engage the cover 15. If the valve member 19 is movedtowards the left, contact is maintained between the inner surface 33 ofthe sealing ring 31 and that part of the frusto-conical surface 22 whichis close to the circular edge 23, due to the installation compression ofthe sealing material and to the action of fluid pressure. However,radial inward movement of the surface 33 is limited by the supportingring 38 and by the small axial length of the radially-extending portion32, whereby separation from the frusto-conical surface 22 readily occursas the lesser diameter portion 21 moves towards the sealing device.Fluid is then enabled to flow from the port 14 to the port 13, and therestriction to flow is at a minimum when the lesser-diameter portion 21lies in register with the sealing device, as shown in the lower part ofFIG. 1.

When the valve member 19 is moved towards the right, the ports 13 and 14are isolated one from the other when the edge 23 engages the innersurface 33. Any tendency for material at the radially inner part of thesealing ring 31 to become trapped under the inner surface of the Iantemring 25, during final closing movement of the valve, is reduced by thelimitation of inward movement of the surface 33 which is provided aspreviously described.

In the alternative form of sealing device shown in FIG. 3, a sealingring 41 has a central portion 42 extending radially between an innersealing face 43 and an outer sealing face 44, and oppositely directedaxially-extending portions 45 and 46 both of which are outwardly definedby the outer sealing face 44. The inner surfaces of the portions 45 and46 are formed with annular recesses 47 and 48 which receive ininterlocking engagement the flanges 52 and 53 of supporting rings 49 and51 respectively.

The sealing ring 31 or 41 may be of natural or synthetic rubber or likeresilient material. Each supporting ring 38 or 49,51 is of hardermaterial having little if any appreciable elasticity, and it may be ofmetal, or of a hard elastomeric material such as nylon or Delrm.

The invention may be applied to other forms of valve including more thantwo ports, and two or more sealing devices spaced apart by lantern ringsor other spacers.

In valves having an assembly of spacers and one or more sealing deviceslocated within a bore in the valve housing, the interlocking engagementof the resilient sealing ring with the supporting ring preventsdisplacement of the sealing ring, due to the collective effect ofadverse dimensional tolerances, into a position in which it wouldmalfunction.

I claim as my invention:

1. A sealing device comprising a sealing ring of resilient materialhaving a radially extending portion and an axially extending portion;the radially extending portion being disposed in cross section wholly atright angles to said axially extending portion, terminating remotelyfrom said axially extending portion in an innermost circumferentialsealing face, and being of constant axial thickness; said radiallyextending and axially extending portions together providing an outercircumferential sealing face; said axially extending portion having aninner circumferential face of a substantially larger diameter than saidinnermost circumferential sealing face; an annular radially outwardlydirected recess being formed, adjacent to said radially extendingportion, in said inner circumferential face of said axially extendingportion; and said device also including a supporting ring of a materialwhich is harder than that of the sealing ring; said supporting ringbeing disposed radially within the axially extending portion and to oneside of the radially extending portion, said supporting ring having aradially outwardly directed flange which is of the same radial depth andaxial width as and closely fits in said annular recess whereby axialinterlocking, and rigid assembly, of said sealing ring and saidsupporting ring is provided solely by engagement of said flange withsaid recess; the diameter of said inner circumferential sealing facebeing only sufficiently less in the free state of the sealing ring thanthe innermost diameter of said supporting ring for that face to have aninterference, and thus fluid sealing, fit with respect to an associatedmember when that member is so positioned as to be in engagement with thesealing ring, while said supporting ring has a clearance fit withrespect to that member.

2. A sealing device according to claim 1 wherein the assembled sealingring and supporting ring have a substantially square cross-section, andthe axial length of the supporting ring exceeds the axial length of theradially-extending portion of the sealing ring.

3. A sealing device according to claim 1, wherein the sealing ring has afurther axially-extending portion on the opposite side of theradially-extending portion from the first-mentioned axially-extendingportion, and wherein a further supporting ring is provided on saidopposite side of the radially-extending portion.

1. A sealing device comprising a sealing ring of resilient materialhaving a radially extending portion and an axially extending portion;the radially extending portion being disposed in cross section wholly atright angles to said axially extending portion, terminating remotelyfrom said axially extending portion in an innermost circumferentialsealing face, and being of constant axial thickness; said radiallyextending and axially extending portions together providing an outercircumferential sealing face; said axially extending portion having aninner circumferential face of a substantially larger diameter than saidinnermost circumferential sealing face; an annular radially outwardlydirected recess being formed, adjacent to said radially extendingportion, in said inner circumferential face of said axially extendingportion; and said device also including a supporting ring of a materialwhich is harder than that of the sealing ring; said supporting ringbeing disposed radially within the axially extending portion and to oneside of the radially extending portion, said supporting ring having aradially outwardly directed flange which is of the same radial depth andaxial width as and closely fits in said annular recess whereby axialinterlocking, and rigid assembly, of said sealing ring and saidsupporting ring is provided solely by engagement of said flange withsaid recess; the diameter of said inner circumferential sealing facebeing only sufficiently less in the free state of the sealing ring thanthe innermost diameter of said supporting ring for that face to have aninterference, and thus fluid sealing, fit with respect to an associatedmember when that member is so positioned as to be in engagement with thesealing ring, while said supporting ring has a clearance fit withrespect to that member.
 2. A sealing device according to claim 1,wherein the assembled sealing ring and supporting ring have asubstantially square cross-section, and the axial length of thesupporting ring exceeds the axial length of the radially-extendingportion of the sealing ring.
 3. A sealing device according to claim 1,wherein the sealing ring has a further axially-extending portion on theopposite side of the radially-extending portion from the first-mentionedaxially-extending portion, and wherein a further supporting ring isprovided on said opposite side of the radially-extending portion.